Graduation Year


Document Type




Degree Granting Department

Computer Science

Major Professor

Miguel A. Labrador, Ph.D.


TCP, Networks, Linux, Performance, Computers


With recent developments in technology broadening the complexity and performance issues of computer networks, more work is being put into studying the behavior of network protocols under various new environments. As it stands today, TCP is the dominant protocol for communicating over the Internet. It has been shown to be reliable and efficient in the relatively low-bandwidth networks it was designed for. With the increasing availability of high-speed optical, wireless, and ad hoc networks, more research is being done to study new TCP variants that will perform well under these new environments. In order to perform such work, researchers require tools to test and observe the properties of the protocols they are studying. This is the case of Web100 [1, 2], a software patch that provides the instrumentation and tools to study and diagnose TCP variables, and Dummynet [3], a tool for shaping network traffic that can be used in conjunction with Web100 to emulate different environments and network conditions.Although these two powerful tools have gained a lot of attention lately, installing and setting up this testbed is not a straightforward task. In this thesis, this is addressed by providing a guide to help researchers and educators reduce the installation time. In addition, the educational benefits of the testbed are shown by conducting a number of experiments under different network conditions and analyzing the behavior of the major mechanisms in TCP. Research potential is demonstrated by integrating the experimental SF-SACK [4, 5] protocol into the testbed and its performance is compared against SACK [6], another more widely used version of TCP. Using the Web100-Dummynet testbed, results are shown illustrating performance measurements such as throughput, fairness, and smoothness.